A typical inkjet printer usually has a carriage that contains one or more fluid-ejection devices, e.g., print heads, capable of ejecting fluid, such as ink, onto media, such as paper. Print heads usually include a carrier and a fluid-ejecting substrate (or print die), e.g., formed from silicon or the like using semiconductor processing methods, such as photolithography or the like.
The print die is typically affixed to the carrier by an adhesive. In many applications, the carrier includes a plurality of ink delivery channels for directing the ink from the ink reservoir to the print die. A surface of the carrier surrounds each of the ink delivery channels and forms ribs on either side of each of the ink delivery channels. Moreover, print dies usually include a plurality of slots that receive the ink from the ink delivery channels and direct the ink to resistors of the print die. A portion of a surface of the print-die surface surrounds each of the slots and forms ribs on either side of each of the slots. The slots of the print die are typically aligned with the ink delivery channels, and each of the ribs of the print die respectively abuts one of the ribs of the carrier.
To affix a print die to a carrier, an adhesive is typically applied to ribs of the carrier and/or the ribs of the print die, e.g., using a capillary tube of a syringe. The ribs of the print die are aligned with the ribs of the carrier and are pressed into abutment with the ribs of the carrier. One problem with this is that adhesive can be forced from between the abutting ribs and into the ink delivery channels of the carrier and/or the slots of print die, causing a blockage to the flow of ink. To correct for this, the amount of adhesive applied to the ribs is often reduced, which can undesirably allow ink to pass from one slot to another or to leak from the print cartridge. Moreover, print dies are becoming smaller and thus print-die and carrier ribs are becoming smaller. For some applications, print-die and carrier-rib sizes are on the order of, or are smaller than, the diameter of the capillary tubes of the syringes used to apply the adhesives, making it difficult to apply adhesive to the ribs. For many applications, capillary tube diameters cannot be reduced any further because increased fluid flow friction associated with reducing the diameter will make it extremely difficult to produce adhesive flow through the capillary tube.
After the print die is affixed to the carrier, the electrical contacts of the print die are electrically connected to the electrical connectors of the carrier using the electrical interconnects. Since many types of ink are corrosive to the electrical contacts, connectors, and interconnects, an encapsulant is usually disposed on the electrical contacts, connectors, and interconnects to protect them from the ink. However, the electrical contacts, connectors, and interconnects are often located adjacent the orifices, and the encapsulant often flows over the orifices, causing the orifices to become clogged. Moreover, many inkjet printers employ a wiper for wiping ink residue from the orifices to prevent the residue from clogging the orifices or from misdirecting ejected ink drops. However, encapsulants often flow to and solidify at a location such that the encapsulant prevents the wiper from effectively cleaning some of the orifices.